/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */
package common;

import java.io.FileInputStream;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 *
 * @author Administrator
 */
@WebServlet(name = "DownloadServlet", urlPatterns = {"/DownloadServlet"})
public class DownloadServlet extends HttpServlet {

    /**
     * Processes requests for both HTTP <code>GET</code> and <code>POST</code>
     * methods.
     *
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    protected void processRequest(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        String link = request.getParameter("link");
        if (!link.isEmpty()) {
            String[] tokens = link.split("//");
            String nome = tokens[tokens.length - 1];
            response.setContentType("application/octet-stream; name=" + nome);
            response.setCharacterEncoding("UTF-8");
            response.addHeader("content-disposition", "attachment; filename=" + nome);
            byte[] dati;
            try {
                FileInputStream fis = new FileInputStream(link);
                dati = new byte[fis.available()];
                fis.read(dati);
                response.setContentLength(dati.length);
                ServletOutputStream out = response.getOutputStream();
                out.write(dati);
                out.flush();
                out.close();
            } catch (IOException e) {
                try {
                    response.getOutputStream().println("Risorsa non più risponibile, contattare l'amministratore di sistema");
                    response.sendError(-99, "Risorsa non disponibile");
                } catch (Exception ex) {
                    // nel caso in cui non si riesca a scrivere sull'output stream
                    return;
                }
            }
        }

    }

    // <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code.">
    /**
     * Handles the HTTP <code>GET</code> method.
     *
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        processRequest(request, response);
    }

    /**
     * Handles the HTTP <code>POST</code> method.
     *
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        processRequest(request, response);
    }

    /**
     * Returns a short description of the servlet.
     *
     * @return a String containing servlet description
     */
    @Override
    public String getServletInfo() {
        return "Short description";
    }// </editor-fold>

}
